What does a NEUTRON STAR become??

Question

does it stay a neutron star forever, or does it die out to someting similar to a black dwarf? (and about black dwarfs.... what EXACTLY are they?? big balls of black matter? do they stay that way forever?)


....................just wondering; we were talking about it in science class............

Answer 1

A neutron star is one of the few possible endpoints of stellar evolution. A neutron star is formed from the collapsed remnant of a massive star after a Type II or Type Ib, or Type Ic supernova.

A typical neutron star has a mass between 1.35 to about 2.1 solar masses, with a corresponding radius between 20 and 10 km (they shrink as their mass increases) — 30,000 to 70,000 times smaller than the Sun. Thus, neutron stars have densities of 8×1013 to 2×1015 g/cm³, about the density of an atomic nucleus.[1] Compact stars of less than 1.44 solar masses, the Chandrasekhar limit, are white dwarfs; above three to five solar masses (the Tolman-Oppenheimer-Volkoff limit), gravitational collapse occurs, inevitably producing a black hole.

Due to its small size and high density, a neutron star possesses a very high rotation speed, as one revolution can take anything from one seven-hundredth of a second to thirty seconds and a surface gravity 2×1011 to 3×1012 times stronger than that of Earth. One of the measures for the gravity is the escape velocity, the velocity needed for an object to escape from the gravitational field to infinite distance. For a neutron star, such velocities are typically 150,000 km/s, about 1/2 of the velocity of light. Conversely, an object falling onto the surface of a neutron star would strike the star also at 150,000 km/s. To put this in perspective, if an average human were to encounter a neutron star, he or she would impact with roughly the energy yield of a 100 megaton nuclear explosion (a power equivalent to twice the tsar bomba, the biggest nuclear weapon ever detonated).

A black dwarf is a theoretical astronomical object, constituting the remains of a Sun-sized star which has fused all of its original hydrogen and helium fuel to heavier elements such as carbon, oxygen and nitrogen and subsequently lost its remaining energy due to radiation. In other words, a black dwarf is a white dwarf that has cooled down so that it no longer emits heat or light. None are known to exist in our universe, as the time taken for a white dwarf to cool to such a degree is hypothesized to be longer than the age of the universe.

Even at the time when black dwarfs exist they may be extremely difficult to detect, emitting very little thermal radiation (if any) at a temperature not much above that of the cosmic microwave background radiation. They may be detectable through their gravitational influence.

Black dwarfs should not be confused with brown dwarfs, which are formed when gas contracts to form a star, but does not possess enough mass to initiate and sustain hydrogen nuclear fusion. "Brown dwarfs" were at times called "black dwarfs" in the 1960s.

Both black dwarfs and white dwarfs are degenerate dwarfs.

I hope this helps you out in your science class young lady. Aloha.

Answer 2

Black dwarfs are burned out cinders, or what's left of a star's core after it dies out. Neutron stars are unstable and erratic dying stars which will eventually exhaust all that energy, and depending on the size of the star, could have different effects. If the star is a medium-sized yellow one such as the sun, it would become a black dwarf, but if it's a more massive blue or white thing such as Rigel which can be found in Orion or Sirus the dog star, it would collapse upon itself and turn into a possible black hole. Realize that black holes are a theory, and we're not totally sure they exist. But there is something truly funny about Cygnus X-1, which makes the scientists suspect that one half of that double star is in fact a black hole. Black holes are just gravity without a form. A more massive star would also cause a supernova after the neutron star phase.

Answer 3

Neutron stars are such exotic beasts that no one is quite sure how they age. Some of them start out as pulsars, their rapid spin and powerful magnetic fields making them like fast-spinning lighthouses. The most powerful of them radiate gamma-ray beacons. However, they gradually slow down, and their radiation drops through x-ray, ultraviolet, optical, infrared, and eventually radio waves. While most of them will just sit there slowly cooling, some in binary star systems produce x-ray or gamma ray bursts when material from their companion star falls on them.

Black dwarf generally refers to a white dwarf that has completely cooled. Theoretically, this takes considerably longer than the age of the universe, so none exist yet.

Here's a site with some good information about neutron stars:

Answer 4

They could turn into a Pulsar- a fast spinning core that flashes like a lighthouse. Leftover cores of stars cool VERY slowly, so most Neutron stars stay that way for a very long time.

Answer 5

The sunlight will quietly die as a nil.fifty one photo voltaic mass white dwarf. For a neutron celeb it nevertheless needs as a lot as 0.40 4 photo voltaic plenty. even with the undeniable fact that, to produce a neutron celeb, you want to have a progenitor mass of five circumstances more suitable than the Chandrasekhar reduce of one million.38 photo voltaic plenty. there is one authentic way, if a star can thieve mass from an excellent spouse. even with the undeniable fact that at in straightforward words a million photo voltaic mass, it needs more suitable than 7 more suitable photo voltaic plenty to rob. that ought to recommend to truly gobble mass from the spouse considering that there is not any such accretion fee obtainable. So the authentic way breaks down and turns into no longer obtainable. i visit imagine of yet in a distinct way. enable 2 low mass white dwarfs of below 0.7 photo voltaic plenty collide! sparkling skies!

Answer 6

Not sure of black dwarfs. I thihk a nuetron star explodes into a supernova which becomes a black hole

Answer 7

Not sure but I think at least some of them become Quasars

Answer 8

Most Type II supernovae leave behind an extremely dense neutron star.
A neutron star is a compact object supported by degenerate-neutron pressure.
Rapidly rotating, strongly magnetic neutron stars produce narrow beams of radiation.

--------------------------------------------------------------------------------

(1) Most Type II supernovae leave behind an extremely dense neutron star.
Just a reminder: A type II supernova occurs when the iron core of a supergiant star collapses to the density of an atomic nucleus (a few hundred million tons per cubic centimeter). At such tremendously high densities, protons and electrons are fused together into neutrons. The relevant reaction is this:
e- + p -> n + neutrino
About 1057 neutrinos are made in the iron core, as the protons (p) are converted to neutrons (n). The billion trillion trillion trillion trillion neutrinos carry off most of the supernova's energy (photons are just a minor byproduct of a supernova).
After its ``bounce'', the star's core settles down as a sphere of tightly packed neutrons, known as a neutron star. A neutron star can be thought of as a single humongous atomic nucleus (containing roughly 1057 neutrons) with a mass between 1 and 3 solar masses, packed into a sphere 5 to 20 kilometers in radius. To put things into perspective, a neutron star is about as big as the beltway around Columbus.

In addition to being amazingly dense, neutron stars have other amazing properties:

Rapidly rotating: up to 1000 rotations/second, compared to 1 rotation/month for the Sun.
Strongly magnetized: up to 1 trillion Gauss, compared to an average of 1 Gauss for the Sun (and 0.5 Gauss for the Earth).
Very hot: initially 1,000,000 Kelvin at the surface, compared to 5800 Kelvin for the Sun.
The surface of a neutron star is not anyplace you would want to visit. The gravitational acceleration is 100 billion g's (that is, 100 billion times the gravitational acceleration at the Earth's surface). The escape speed at the surface of a neutron star is half the speed of light (that is, 150,000 km/sec, versus a paltry 11 km/sec for the Earth). On the surface of a neutron star, you'd be simultaneously vaporized by the intense heat and squashed flat by the intense gravitational force.
--------------------------------------------------------------------------------

(2) A neutron star is a compact object supported by degenerate-neutron pressure.
Neutrons, like electrons, must follow the laws of quantum mechanics. In particular, they must obey the Pauli exclusion principle, as outlined in last Thursday's lecture. The existence of neutron stars was actually first predicted in 1933, only a year after the discovery of the neutron.
At a density of 1 ton/cm3, electrons are degenerate, and provide degenerate-electron pressure.

At a density of 400 million tons/cm3, neutrons are finally degenerate, and provide degenerate-neutron pressure.

The interior structure of a neutron star is fairly uncertain. (We don't know a lot about how matter behaves at these amazingly high densities.) One proposed model looks like this:


Just as there is an upper limit on the mass of a white dwarf, there is an upper limit on the mass of a neutron star. White dwarfs can't have M > 1.4 Msun; above this mass, the degenerate-electron pressure is insufficient to prevent collapse. Neutron stars can't have M > 3 Msun; above this mass, the degenerate-neutron pressure is insufficient to prevent collapse (the upper mass limit for neutron stars is fairly uncertain). If a dense object is too massive to be a white dwarf or a neutron star, it's BLACK HOLE TIME (more about black holes next week..)

It's certainly true that the laws of quantum mechanics predict the existence of neutron stars. However, how can we detect them, to verify that they actually exist? Well, neutron stars may be tiny, but they are also hot, and hence produce a significant amount of blackbody radiation.

R = 15 km = 0.00002 Rsun
T = 1,000,000 K = 170 Tsun
Therefore, L = (0.00002)2 (170)4 Lsun = 0.3 Lsun
At a temperature of 1,000,000 Kelvin, the wavelength of maximum emission is at 2.9 nanometers -- in the X-ray range. We can hunt for hot neutron stars by looking for X-ray sources. Although most of the light from neutron stars is emitted at X-ray wavelengths, the nearest neutron star can also be glimpsed at visible wavelengths.
--------------------------------------------------------------------------------

(3) Rapidly rotating, strongly magnetic neutron stars emit narrow beams of radiation.
Although neutron stars do emit blackbody radiation, they are not simply boring spherical blackbodies, as stars are. Neutron stars have additional ways of emitting electromagnetic radiation. The strong magnetic field and rapid rotation of a neutron star make it a very potent electrical generator. (Here on Earth, commercial electrical generators work by rotating a series of magnets inside a coil of wires. The essential point is that you need to have a magnetic field in motion.) The electric field generated by the rotating magnetized neutron star is strong enough to rip charged particles (such as electrons) away from the surface of the neutron star.
The charged particles follow the magnetic field lines to the north and south magnetic poles of the neutron star. (Remember, when I discussed the magnetic field of the Sun, I pointed out that charged particles move most readily along the magnetic field lines, rather than perpendicular to them.) The accelerated particles produce intense but narrow beams of radiation, pointing away from the two magnetic poles. We can see one of these beams of light ONLY if it is pointing toward us, just as we see the light from a flashlight only when it is pointing toward us.

A complicating factor is that on a neutron star, just as on Earth, the magnetic poles don't coincide with the rotational poles. Thus, the beams of radiation pointing away from the magnetic poles are at an angle to the rotation axis of the neutron star; as the neutron star rotates, the beams swing around in a cone. If a beam happens to sweep across our location in space, we see a brief flash of light. (This is sometimes known as the ``Lighthouse effect''. If you are down by the shore at night, you see lighthouses emit a blinking light. This is not because the lamp in a lighthouse is turned off and on, but because it inside a searchlight which is rotated around and around. As the beam of light from the searchlight sweeps across your location, you see a brief flash of light.)